Textile finishing process



Jan. 7, 1958 K. H. BARNARD ETAL TEXTILE FINISHING PROCESS Filed Jan. 18, 1954 KENNETH H. aARNARo JAMES N. GRowNx-:Y

T. .SMM

ATTORNEY Unite TEXTILE FINISHING PROCESS Application January 18, 1954, Serial No. 404,764 16 Claims. (Cl. 117-10) This invention relates to textile finishing processes.

Numerous water-soluble resins have been employed in the textile industry in the production of embossed fabrics having a raised or relief configuration thereon as well as in friction calendering processes wherein a high gloss has been imparted to the cloth. Some of the resins so employed have simultaneously produced other desirable effects, such as reducing shrinkage of the cloth and imparting crease resistance also. However, these finishing processes have a number of limitations and deficiencies; for example, many formulations have tended to build up on Schreiner calender rolls to the extent where the grooves on the rolls have been blocked or filled with the resinous composition which resulted in an uneven finish on the goods being processed. In addition there is no satisfactory method of controlling the luster or degree of glossiness except by varying the quantity of resin applied, so when the resin deposit was reduced sufficiently to produce a 'soft satiny luster the dimensional stability and relative crease resistance of the cloth were also impaired. The most serious defect in the prior art processes has been the severe loss of tear strength which is an important matter, especially in connection with the relatively thin fabrics which are so commonly subjected to a mechanical finishing treatment. Many fabrics embossed and glazed by known methods also had an undesirably rrn hand for many uses. The known treatments also often fail to produce a durable finish, able to withstand repeated laundering or dry cleaning operations without substantial loss of luster or embossed design.

An obect of the invention is to provide an improved method for mechanically finishing textile fabrics with excellent retention of the original tear strength of the fabric.

Other objects and advantages of the invention will be apparent to those skilled in the `art from the detailed description hereinbelow.

The present invention concerns impregnating a textile fabric with an aqueous dispersion of a heat-reactive, waterdispersible aminoplast of the group consisting of methylol melamines and methylol and alkoxymethyl derivatives of diamides, formamide, urea and modified ureas in conjunction With a mixture of a lower alkylated methylol melamine with a compound free of basic salt-forming groups and containing an alkyl radical of at least 7 carbon atoms and a single nitrogen atom having attached thereto a carbonyl radical and a reactive `substituent of the group consisting of hydrogen and alkylol radicals; partially drying the impregnated fabric; mechanically finishing the moist fabric under heat land pressure; and drying and curing the treated fabric until the finish is substantially water-insoluble, whereby a mechanically-nished resintreated fabric of improved tear strength is obtained. vNarrower aspects of the invention relate to specific types of mechanical finishing such as oalendering with friction calenders or embossing calenders, particular types of substances as components of the impregnating bath, moisture content of the impregnated fabric during calendering and proportions of bath ingredients.

atent O ice The novel process produces an outstanding and unexpected improvement in the tear strength of mechanicallynished resin-treated fabrics by incorporating in the resin treating bath a mixture of an alkylated methylol melamine and an amido compound containing a higher alkyl radical. In addition a number of other benefits are obtained with the new treatment including improved durability of the glaze or embossed print on the fabric, better abrasion resistance, durable spot resistance, a softer hand, a higher degree of durable water repellency, control of the luster as well as the shrinkand crease-resistance usually imparted by the aminoplast resin. Moreover there is far less tendency of the finish to build up and clog the Schreiner lines or other engravings on the embossing rolls. Control of the luster of the finished fabric is readily obtained by varying the ratio of the amido compound to the total resin-forming compounds present in the impregnating bath.

A broad variety of heat-reactive, water-soluble, resinforming aminoplasts may be employed in the present invention. Of these, the preferred aminoplasts are the spraydried diand trimethylol melamines, monoand dimethylol ureas, monoand dimethylol ethylene-ureas Iand their ethers, methylated methylol ureas and mixtures thereof in either monomeric form or as Water-soluble partially polymerized materials. These substances all yield excellent results and are among the principal commercial textile treating resins in use |at the present time. A number of the urea condensates listed above fall within the category of condensates of modified ureas which term is used herein to include alkyl ureas, alkylol ureas, cyclic ureas and thiourea's. Good results are also obtainable with many other aminoplastm including ethanolurea, methyl urea, formamide, oxamide, succinamide, adipamide, ethylenediamine-bis(acetamide), propylene urea, dihydrouracil, piperazine, and acetylene diurea in the form of their methylol derivatives or condensation products with formaldehyde, and water-soluble ethers of lower alcohols such as methyl and ethyl alcohol with such condensation products, and the like,

Along with one or more of the aforesaid aminoplasts in the aqueous impregnating bath there is incorporated a mixture prepared as described in either Thurston Patent No. 2,357,273 or Cathers et al. Patent No. 2,491,249. The term mixture is used herein to include either physical mixtures or reaction products of a lower alkylated methylol melamine and certain compounds in the same manner as in the aforesaid Thurston patent, inasmuch as it still has not been determined with certainty that a reaction occurs in the praparation of the mixtures of the aforesaid Thurston Patent. Moreover it has been found that after producing a mixture of the type disclosed by Thurston, an additional amount within limits of the alkylated methylol melamine may be added to that mixture without heating to provide a mixture operative in the novel process. Suitable methylol melamine ethers include those which have been alkylated with alcohols having from one to four carbon atoms. Methylated methylol melamines are highly preferred because of their water solubility. Ethylated or butylated methylol melamines have to be applied in emulsion form since they are not soluble in water. To date the best results have been obtained with a two-thirds methylated condensation product which may be described as a mixture comprising essentially dirnethylated trimethylol melamine. The other component of the Thurston mixture is an amido or alkylolamido compound containing an alkylated radical of at least 7 carbon atoms. Among the many substances disclosed are caprylamide, capramide, lauramide, myristamide, palmitamide, stearamide, oleamide, liuoleamide, ricinoleamide, N- methyl stearamide, N-ethyl lauramide, methylol lauramide, ethanol stearamide, octyl carbamate, dodecyl carbamate, N-methylol octadecyl carbamate, and the like, as well as mixtures thereof. Por the purposes of the present invention N-methylol amides of aliphatic acids containing at least 12 carbon atoms are preferred as these appear to give the optimum results. Outstanding results have been obtained with N-methylol stearamide. Methods for the t preparation of the two components andtmixtures thereof using sodium isopropyl napthalene sulfonate or another suitable dispersing agent in forming an aqueous dispersion are described in detail in the two patents mentioned above and need not be repeated here.

In the novel process described herein, the weight ratios of amido compound to alkylated methylol melamine can be varied somewhat from those described in the Thurston patent. For example, between about 0.05 and about 2.0

i parts of the amido compound may be present per part of the melamine compound and the preferred ratios range from 0.5:1 to l.5:1.

In preparing a pad bath for the present process between about 5 and about 300 parts by weight and preferably between 50 and 150 parts, of the mixture of amide and melamine compound should be present for each 100 parts of the aforesaid aminoplast on a basis of weights of dry solids. In addition, the treating bath should be kept on the alkaline side with a pH ranging between about 7.0 and about 11.0, and preferably between about 8.0 and about 9.0, l

to avoid precipitation in the bath. In the case of wool or other materials susceptible to damage by alkaline solutions, the lower part of these ranges is recommended. Ammonia is especially recommended for adjusting the pH of the bath, but other alkaline materials may also be used including morpholine, triethanolamine, etc. Although not absolutely essential, it is often desirable to buffer the bath with a small amount of dicyandiamide or other suitable buffering compound in small amount as, for example, from 0.5 to 1.0 percent of the weight of the bath.

In order to accelerate the curing of the resin-forming mixture to a degree feasible for use in commercial finishing plants, a conventional curing agent for thermosetting amino resins should be present when the impregnated fabric is cured after the mechanical finishing operation. The catalyst or accelerator is desirably added to the treating bath in order to simplify operation and this agent should be of a type which is compatible with any ingredient, in the alkaline treating bath. Among the many such catalysts are ammonium sulfate, diammonium phosphate, triethanolamine hydrochloride and ammonium chloride. The optimum quantity of accelerator will, of course, vary somewhat with the substance selected but, in general,

about l to about 30 percent of catalyst, based on the total weight of the resin solids in the impregnating bath should be used and the preferred range is from about 3 to about percent. The pad bath concentration and the squeeze rolls should be adjusted to provide an add-on or pickup amounting to between about 2 and about 10% .solids based on the dry weight of the fabric.

While especially adapted to the treatment of cotton fabrics, the treatment described herein is applicable to any woven, knitted or felted textile material which is capable of being glazed or embossed, This includes fabrics made up in whole or in part of the fibers of cotton, viscose rayon, euprammonium rayon, cellulose acetate, Wool, silk, flax, linear polyamides such as nylon, homoand copolymers of acrylonitrile, polyesters such as polyethyleneglycol tcrcphthalate, and so forth.

The expression mechanical finishing under heat and pressure is used herein in connection with continuous calendering by passage of the fabrics through either a friction calender or an embossing calender in which at least one heated roll is used. Schreiner embossing calenders are included along with those which have deeper print patterns. Prior to this operation, the impregnated fabric from the treating bath must be dried to a moisture content between about 3 and about 20% by weight, 6 to 12% being recommended for optimum results. This partial 4 drying operation may be carried out on conventional apparatus operating at temperatures of the order of 180o F. Where a glazed finish is to be imparted to the cloth. frame drying is preferred with the frame set to stretch thc goods to between l and 1.25 inches wider than the finished width to provide the additional width necessary to malte up for the warpwise pull of the polishing or glazing calenders. Althoughy the impregnated fabric may be stored for some time under conditions suitable for maintaining the stated moisture content, or may be dried completely and later dampened to the specified content of water, the fabric is usually subjected to the mechanical-finishing operation immediately after it has been partially dried. The polishing or embossing roll is heated to a conventional temperature of 300 to 400 F. and this metal roll is forced against a paper or cloth roll under a conventional pressure such as 4,000 to 12,000 pounds per linear inch of nip. The metal polishing roll of the friction calender is run at a linear peripheral speed of about 2.5 to 4 times that of the adjacent roll. Two passes through the fraction calendar are recommended for most materials. lmpregnating compositions of the nature of those described above have been found far less subject to sticking to the Schreiner rolls or other embossing rolls containing relatively tine indentations. Thus there is substantially no tendency of the solids to build up on the rolls and produce an uneven finish.

After the mechanical nishing operation, the glazed or embossed fabric is dried and cured, preferably in a single operation, until the finish is converted substantially to the water-insoluble state, subject, of course, to the usual precautions against damaging the particular fabric by cxcessive heating. The material may be dried and cured in conventional apparatus operating at temperature rang ing from about 180 F. up to about 500 F. for a period of between 10 seconds and 30' minutes with the curing time decreasing as the temperature increases; however, curing for l to 10 minutes with equipment maintained at 250 to 350 F. is recommended in most cases. Then the usual process wash may be employed, if desired, followed by drying in the customary manner.

For a better understanding of the objects and nature of this invention, reference should be had to the accompanying examples which are of an illustrative rather than a limiting nature, and in which al1 proportions are given in terms of weight unless otherwise stated therein.

For comparative purposes all of the examples below employ formulations which are applied to two similar cotton fabrics and friction-calendered under substantially the same conditions to produce glazed chintz. However, it is known from experience that comparable tear strength, durability of finish and spray rating are obtainable on em bossing under similar conditions provided that an embossable fabric is employed.

The baths containing the dispersions used in the present invention are adjusted with concentrated ammonium hydroxide (29% NH3) to a pH of 8.5. These, as well as the pad baths of the comparative examples designated with letters, were stable at room temperature for more than eight hours without hydrophobing after addition of a conventional curing catalyst.

In Examples B, C, D and 1 to 5, an 80 x 92 cotton pereale is impregnated in the pad bath to a wet pick-up of based on the dry fabric weight using one dip and one nip under a pressure of 2.8 tons; then, the fabric is dried for one minute at 225 F. to a moisture content of 5-7% and friction-calendered, using a two passes and 20 tons total pressure in a 33 inch wide calender with the heated roll maintained at 350 F. After this all samples of the fabric are cured for 3 minutes at 325 F. on a pin tenter and subjected to a conventional process wash. The

same conditions are used in Examples E, 6 and 7 on an 80 X 8O cotton percale except for using two dips and two nips under a pressure of 2.9 tons for padding and drying for 2 minutes at 200 F. Example A sets forth the gloss, spray rating and tear strength of both percales in the untreated and uncalendercd state.

with said alkylated methylol melamine and at least one of said aminoplasts.

2. A process according to claim l in which said com- Examples A B 1 C 2 D Percent Dry Add On:

Methylated Trimethylol Melamine 0. 5 1. 0 N-Methylol Stearamide-. 0. 5 1. 0 Dlmethylol Ethylene Urea-.. 4. 8 4.8 Bis-methoxy methyl Urea 4. 8 4. 8

Dimethylol Me1an1ine Mixed Monoand D- rnethylol Urea Partially Polymerized Urea-Formaldehyde Gloss Reading:

Initial After 3 washes-. Elmendort' Tear Strength.. A. A. T. C. Spray Rating:

Intr After 3 washes 18 (i 13 7 11 1. 5 l. 5 l. 2 1. 4 1.3

The laundering employed in connection with testing the durability of the gloss and spray ratings consists of three l0 minute hand washes in mild soap suds at 100 F. followed by a l0 minute-rinse in water at 100 F. and air drying in each case.

Gloss values are arbitrary using a Hunter portable 6() degree glossmeter with the reading on the washed, untreated, uncalendered cotton percale designated as 0 and the highest gloss obtainable thereon in conventional commercial glazing designated as 100.

Spray ratings are made according to A. A. T. C. C. Standard Test Method No. 22-52.

Upon reference to the tabulated data above it, it is apparent that a substantial increase in fabric tear strength is obtained over every comparative example designated by a letter when the procedure of the present invention is followed as in the examples designated by numerals. ln the numbered examples it will be noted that the tear strength either equals or closely approaches that of the original untreated, uncalendered fabric. Moreover, the spray ratings indicate a durable and fairly high waterrepcllency. From the gloss measurements, it will be appreciated that a wash-durable finish is obtained and that the process is adaptable to producing a substantial range of lusters.

Since variations may be made in the process described above by those skilled in the art without departing from the scope of the present inventive concept, the present claims are intended to cover such modifications and to be limited only by the language therein or as required by the prior art. Y

Reference is made to the accompanying self-explanatory drawing which explains pictorially what has already been disclosed in the specification.

We claim:

l. A process which comprises impregnating a textile fabric with an aqueous dispersion of a heat-reactive wateredispersible aminoplast of the group consisting of unsubstituted methylol melamines, and methylol and alkoxymethyl substituted diamides, formamide, urea, alkyl ureas, alkylol ureas, cyclic ureas and thioureas together with a mixture comprising a lower alkylated inethylol melamine having alkyl radicals containing not more than 4 carbon atoms and a compound free of basic salt-forming groups and containing an alkyl radical of at least 7 carbon atoms and a single nitrogen atom having attached thereto a carbonyl radical and a reactive substituent of the group consisting of hydrogen and alkylol radicals; partially drying the impregnated fabric; calendering the moist fabric under heat and pressure, and drying and curing the treated fabric until the finish is substantially water-insoluble, to produce a mechanically-finished resin-treated fabric of improved tear Strength relative to the same fabric treated individually pound comprises an N-methylol amide of a fatty acid containing at least l2 carbon atoms and in which the moist treated fabric is friction-calendered.

3. A process according to claim l in which said compound is an N-methylol amide of a fatty acid containing at least l2 carbon atoms and in which the moist impregnated fabric is embossed on an embossing calender.

4. A process which comprises impregnating a textile fabric with an aqueous dispersion of a heat-reactive water-dispersible aminoplast of the group consisting of unsubstituted methylol melamines, and methylol and alkoxymethylol substituted diamides, formamide, urea, alkyl ureas, alkylol ureas, cyclic ureas, cyclic ureas and thioureas together with a mixture comprising a methylated methylol melamine and N-methylol steararnide; partially drying the impregnated fabrc to a moisture content of between about 3 and about 20%; calendering the moist fabric under heat and pressure; and drying and curing the calendered fabric until the finish is substantially water-insoluble to produce a calendered resin-treated fabric of improved tear strength relative to the same fabric treated individually with said methylated methylol melamine andat least one of said aminoplasts.

5. `A process according to claim 4 in which said aminoplast comprises dimethylol ethylene urea.

Y 6. A process according to claim 4 in which said aminoplast comprises a rnethylol melamine.

7. A process according to claim 4 in which said aminoplast comprises a methylol urea.

8. A process according to claim 4 in which said aminoplast comprises a methylated methylol urea.

9. A process which comprises impregnating a textile fabric with an aqueous dispersion of a heat-reactive water-dispersible aminoplast of the group consisting of unsubstituted methylol melamines and methylol and alkoxymethyl substituted diamides, formarnide, urea, alkyl ureas, alkylol ureas, cyclic ureas and thioureas together with a mixture comprising a methylated methylol melamine with an N-methylol amide of a fatty acid containing at least l2 carbon atoms; partially drying the impregnated fabric to a moisture content of between about 3 and about 20% glazing the moist fabric under heat and pressure in a friction calender; and drying and curing the glazed fabric until the finish is substantially water-insoluble, to produce a glazed resin-treated fabric of improved tear strength relative to the same fabric treated individually with said methylated methylol melamine and at least one of said aminoplasts.

l0. A process according to claim 9 in which said N- methylol amide comprises N-methylol stearamide.

ll. A process according to claim l0 in which said aminoplast comprises dimethylolethylene urea.

12. A process which comprises impregnating a textile fabric with an aqueous dispersion of parts by weight of a heat-reactive water-dispersible aminoplast of the group consisting of unsubstituted methylol mel-amines and methylol and alkoxymethyl substituted diamides, formamide, urea, alkyl ureas, alkylol ureas, cyclic urea and thioureas together with between about 5 and about 300 parts of a mixture comprising 100 pounds of methylated methylol melamine and between about 5 and about 200 pounds of an N-methylol amide of a fatty acid containing at least 12 carbon atoms in sufficient amount to deposit between about 2 and about 10 percent solids based on the dry Weight of the fabric; partially drying the impregnated fabric to a moisture content of between about 3 and about 20%; glazing the moist fabric under heat and pressure in a friction calender; and drying and curing the glazed fabric until the finish is substantially water-insoluble, to produce a glazed fabric of improved tear strength relative to the same fabric treated individually with said methylated methylol melamine and at least one of said aminoplasts,

13. A process which comprises impregnating a textile fabric with an aqueous dispersion of a heat-reactive water-dispersible aminoplast` of the group consisting of unsubstituted methylol melamines, and methylol and alkoxymethyl substituted diamides, formamide, urea, alkyl ureas alkylol ureas, cyclic ureas and thioureas together with a mixture comprising a methylated methylol melamine and an N-methylol amide of a fatty acid containing at least l2 carbon atoms; partially drying the impregnated fabric to a moisture content between about 3 and about 20% by weight; embossing the moist fabric by pressing it between rolls of suitable relief configuration while simultaneously heating the fabric; and drying and curing the treated fabric until the nish is substantially water-insoluble, to produce an embossed fabric of improved tear strength relative to the same fabric treated individually with said methylated methylol melamine and at least one of said aminoplasts.

methylol amide comprises N-rnethylol steal-amide.

l5. A process according to claim 14 in which said aminoplast comprises dimethylol ethylene urea.

16. A process which comprises impregnating a textile fabric with an aqueous dispersion of 100 parts by weight of a heat-reactive water-dispersible aminoplast of the group consisting of unsubstituted methylol melamines and meihylol and alkoxymethyl substituted diamides, form amide, urea, alkyl ureas, alkylol ureas, cyclic ureas and thioureas together with between about 5 and about 300 parts of a mixture comprising 100 pounds of methylated mcthylol melamine and between about 5 and 200 pounds of an Nmethy1ol amide of a fatty acid containing at least 12 carbon atoms in suliicient quantity to deposit between about 2 and about 10 percent solids based on the dry weight of the fabric; partially drying the impregnated fabric to a moisture content between about 3 and about 200% by weight; embossing the moist fabric by pressing it between rolls of suitable relief configuration while simultaneously heating the fabric; and drying and curing the treated fabric until nish is substantially water-insoluble, to produce an embossed fabric of improved tear strength relative to the same fabric treated individually with said methylated methylol melamine and at least one of said aminoplasts.

U. S. DEPARTMENT OF COMMERCE PATENT OFFICE CERTIFICATE OF CORRECTION Patent NoQ 2,81%1'79 January 7, 1958 Kenneth H., Barnard et el umbered patent requlrlng correction and that the said Letters Patent should read as corrected below.

It i'e hereby certified that error appears in the printed specification of the above n Column 4, line 20, for "fraction" read `mirietiche-u; column 6, line 34,- strike out "cyclic urea-LSU, second occurrence; column 8, line 1'7, for "about 200%" read mabout 20%-=f Signed and sealed this llth day of March 1958o SEAL) l Attest:

KARL H., AXLINE ROBERT C. WATSON Attesting Officer Comnissioner of Patents 

1. A PROCESS WHICH COMPRISES IMPREGNATING A TEXTILE FABRIC WITH AN AQUEOUS DISPERSION OF A HEAT-REACTIVE WATER-DISPERSIBLE AMINOPLAST OF THE GROUP CONSISTING OF UNSUBSTITUTED METHYLOL MELAMINES, AND METHYLOL AND ALKOXYMETHYL SUBSTITUTED DIAMIDES, FORMAMIDE, UREA, ALKYL UREAS, ALKYLOL UREAS, CYCLIC UREAS AND THIOUREAS TOGETHER WITH A MIXTURE COMPRISING A LOWER ALKYLATED METHYLOL MELAMINE HAVING ALKYL RADICALS CONTAINING NOT MORE THAN 4 CARBON ATOMS AND A COMPOUND FREE OF BASIC SALT-FORMING GROUPS AND CONTAINING AN ALKYL RADICAL OF AT LEAST 7 CARBON ATOMS AND A SINGLE NITROGEN ATOM HAVING ATTACHED THERETO A CARBONYL RADICAL AND A REACTIVE SUBSTITUENT OF THE GROUP CONSISTING OF HYDROGEN AND ALKYLOL RADICALS; PARTIALLY DRYING THE IMPREGNATED FABRIC; CALENDERING THE MOIST FABRIC UNDER HEAT AND PRESSURE, AND DRYING AND CURING THE TREATED FABRIC UNTIL THE FINISH IS SUBSTANTIALLY WATER-INSOLUBLE, TO PRODUCE A MECHANICALLY-FINISHED RESIN-TREATED FABRIC OF IMPROVED TEAR STRENGTH RELATIVE TO THE SAME FABRIC TREATED INDIVIDUALLY WITH SAID ALKYLATED METHYLOL MELAMINE AND AT LEAST ONE OF SAID AMINOPLASTS.
 4. A PROCESS WHICH COMPRISES IMPREGNATING A TEXTILE FABRIC WITH AN AQUEOUS DISPERSION OF A HEAT-REACTIVE WATER-DISPERSIBLE AMINOPLAST OF THE GROUP CONSISTING OF UNSUBSTITUTED METHYLOL MELAMINES, AND METHYLOL AND ALKOXYMETHYLOL SUBSTITUTED DIAMIDES, FORMAMIDE, UREA, ALKYL UREAS, ALKYLOL UREAS, CYCLIC UREAS, CYCLIC UREAS AND THIOUREAS TOGETHER WITH A MIXTURE COMPRISING A METHYLATED METHYLOL MELAMINE AND N-METHYLOL STEARAMIDE; PARTIALLY DRYING THE IMPREGNATED FABRC TO A MOISTURE CONTENT OF BETWEEN ABOUT 3 AND ABOUT 20%; CALENDERING THE MOIST FABRIC UNDER HEAT AND PRESSURE; AND DRYING AND CURING THE CALENDERED FABRIC UNTIL THE FINISH IS SUBSTANTIALLY WATER-INSOLUBLE TO PRODUCE A CALENDERED RESIN-TREATED FABRIC OF IMPROVED TEAR STRENGTH RELATIVE TO THE SAME FABRIC TREATED INDIVIDUALLY WITH SAID METHYLATED METHYLOL MELAMINE AND AT LEAST ONE OF SAID AMINOPLASTS. 